In the art, it is possible to achieve one-way real-time latency measurement by using synchronized clocks, such as GPS technology. It is possible to use the standard NTP protocol to achieve a level of synchronization between nodes, as described in Mills, D “Network Time Protocol (Version 3) specification, implementation and analysis”, IETF RFC 1305, University of Delaware, March 1992. However, the NTP mechanism does not have a very high accuracy.
In US2003/0048811 A1, with the title “Methods, systems and computer program products for synchronizing clocks of nodes on a computer network”, discloses an algorithm for clock synchronization between two nodes using virtual clocks, a generalization of the clock synchronization for many nodes, and using many round-trip-delays to compute an average one-trip delay. A key feature of the invention described in the US document, is that, each node manages a virtual clock for every other node it synchronizes with.